Investigation on Rates of a Reaction.

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Introduction

2nd March 2003 Investigation on Rates of a Reaction Introduction A reaction takes place when two different molecules collide; this is only possible when the particles have enough kinetic energy. This energy requirement is called the activation energy (AE). The rate of a reaction can be altered by the following: - - Temperature - Catalyst - Concentration - Surface Area Below shows a graph, this illustrates the effect which the above have on a reaction:- We can measure the rate of a reaction by doing the following: - * Measuring how long it takes for a certain volume of CO2 takes to be produced. * Timing how long it takes until the reaction stops. * Measuring the loss in mass of the reactant over time. Aim To investigate the effect that concentration has on the rate of a reaction. Scientific Theory The rate of a reaction can be affected by 4 things (stated above) below show what these are and how they alter the rate of a reaction. * Temperature - The higher the temperature the greater the amount of kinetic (movement) energy is available. Therefore the more energy that the particles have the faster the molecules move and the greater the chance that they will collide with the reactant. ...read more.

Middle

increases the speed at which the reaction occurs will also therefore the higher the concentration the faster the reaction takes place. In this view by doubling the concentration theoretically the time taken should half. Apparatus Here is a list of equipment that I will be using during this experiment: - * 25 x test tubes * 5 x test tube racks * 500 ml x hydrochloric acid (HCl) * 160 ml x distilled water * 25 cm x magnesium ribbon (mg) * 1 x medium beaker * 1 x bung * 1 x measuring cylinder * 1 x scissors * 1 x stop watch * 1 x pencil, pen (to label the test tubes) and table for results Method Here is an account of how I will be doing the actual experiment (based on the pilot experiment) * Collect the test tubes and place them in the racks, cut magnesium ribbon and collect the acid and distilled water, measure out the following: - * 20 ml of acid (2 moles of acid) * 17.5 ml of acid and 2.5 ml of D. water (1.75 moles ") * 15 ml of acid and 5 ml of D. water (1.5 moles ") * 10 ml of acid and 10 ml of D. ...read more.

Conclusion

I believe that I repeated my results a suitable amount of times to get a reliable average and I think that my range of results was enough to complete the investigation with suitable proof. Yet based on the information above I could say that the data may not be sufficiently accurate to support a conclusion, despite the fact that my results were as I had expected the question arises that if my results had have been more precise would my results have been different. My result didn't follow a specific pattern but they did decrease as I increased the concentration. If I were to develop this investigation further I would almost certainly repeat the experiment taking into account the information above (possible reasons for the anomalie), by doing this I will be able to establish the whether or not the investigation that I performed this time was inaccurate. If I were to explore other areas of this topic I would look at different metals and how they affect the rat of a reaction, different acids and see what effect they have and I would possibly look into one of the aspects of my scientific knowledge. END OF INVESTIGATION Carly McKenzie 13330 6099 ...read more.

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